The present invention relates in general to a cartridge for a ribbon, tape or the like for use with a high speed printer, and is concerned, more particularly, with a cartridge for an inked ribbon arranged in an endless, preferably a mobius, loop. The cartridge of this invention is constructed for use either in a stationary position relative to the printer or piggybacked to the moving printing head.
Advancements in the field of mini-computer and micro-computer systems have required compatible advances in the devices used to record or print-out computer information. The drastic increase in computer machine speed has resulted in the output information being printed at a much higher rate than was the case several years ago. For example, an IBM typewriter can operate at a speed of approximately three and one-half characters per second. Today, so-called dot matrix printers operate at speeds at approximately 80-300 characters per second. Because of these drastically increased computer print-out speeds, the disposable print-out devices are quite quickly consumed in printing out millions of characters a day. Presently, cartridge-type disposable ribbon systems are utilized to present an inked ribbon between the printing device and the paper or other material upon which the printing is to take place. The disposable devices usually contain several components thus resulting in each cartridge device being relatively expensive. As computer speeds contine to increase, more disposable devices are used each week per machine.
In the past, one means of presenting and cycling the printer ribbon has been a reel-to-reel arrangement, as in a conventional typewriter. With increased performance, which characterizes the present trend in small matrix printers, rates of print delivery have been increased to such an extent that the operators are changing and rethreading the ribbon virtually on a daily basis. It is because of this inconvenience in making changes with the reel-to-reel arrangement, that there has developed a trend in the industry toward the use of disposable (clean-hands) ribbon cartridges, of which there are several examples available on the market.
The known disposable cartridges are generally somewhat complex in construction having a relatively large number of component parts which may typically be in the range of six to ten parts, which makes these cartridges quite expensive. Accordingly, one object of the present invention is to provide an improved cartridge design substantially reducing the number of components comprising the cartridge so that the cost of the cartridge is substantially reduced. In view of today's use of computer equipment, such a reduction in price is quite significant especially when considered over an entire year of operation.
One typical ribbon cartridge is shown in the Matuck, et al U.S. Pat. No. 3,941,231. This patent shows a ribbon cartridge for an endless loop ink ribbon, suitable for use with a wire matrix printer in which the cartridge includes elongated guide members to confine the path of the loop of the ribbon to a predetermined path along its entire exposed length. In Matuck, et al the cartridge is limited in its use to a piggyback position on the printing head and cannot be used in a stationary position as with the cartridge of this invention.
Accordingly, another object of the present invention is to provide a ribbon cartridge that is constructed to permit use of the cartridge either in a stationary position or piggybacked to the printing head.
Other patents that show ribbon cartridge include U.S. Pat. Nos. 3,621,968; 3,833,108; 3,877,561; 3,927,746; 3,985,219; 3,978,965; 3,897,866; 3,830,351; 3,814,231; 3,799,315; 3,804,227; 3,777,871; 3,980,171; 3,904,017; 3,425,531; 3,425,532; 3,356,202; 3,151,724; 3,094,204; 3,045,800; 3,065,837.
A further object of the present invention is to provide a ribbon cartridge having means for supporting a section of the ribbon to provide the twist in the mobius loop path, at the same time providing the necessary tensioning in the ribbon. In this regard in accordance with the invention upper and lower offset ribs are provided for controlling the twist; with the depth of penetration of one rib relative to the other being controlled to in turn control the tension in the ribbon which can be selected to meet certain printer requirements. Thus, there is provided in accordance with the invention a combined means for simultaneously insuring ribbon rotation or twist and at the same time selectively generating ribbon tension without the use of many parts to the cartridge.
Still another object of the present invention is to provide peeler means in association with the pinch roller of the cartridge for properly directing the loop and preventing any snagging of the endless loop.
Still a further object of the present invention is to provide an ink ribbon cartridge wherein the ribbon is capable of withstanding several million characters of printing, is disposable, relatively simple in construction, lightweight, and inexpensive to manufacture.